Abstract: In order to guide the design of chamber injector for full-flow stage combustion engine, reduced-scale test of gas-gas combustion similarity in a chamber with quartz windows was conducted utilizing gaseous oxygen and gaseous hydrogen as propellants. The high-speed camera was used to obtain the combustion flame structure near the exit of the coaxial injector under the stable combustion and unstable combustion, and the frequency characteristics of unstable combustion were analyzed. The results show that, with the types of propellant, propellant temperature, propellant mixing ratio, combustion chamber and nozzle structure size unchanged, by increasing propellant flow rate, the stable and unstable combustion flame structure is similar to some extent, and the frequency of unstable combustion is the same.

Key words: Full flow stage combustion cycle engine;Injector;Gas-gas combustion;Similarity;Reduced-scale

摘要： 为指导全流量补燃循环发动机推力室全尺寸气气喷注器设计，采用气氢/气氧推进剂，在带可视化窗口的燃烧室中开展了气气燃烧流场相似性缩尺试验研究。采用高速摄影仪获得了不同流量工况下，同轴剪切喷嘴稳定燃烧和不稳定燃烧两种状态下近喷嘴区域的燃烧火焰结构，并分析了不稳定燃烧的频率特性。结果表明：在保持推进剂种类、推进剂混合比、推进剂温度、燃烧室及喷嘴结构尺寸不变的情况下，随着喷嘴流量的逐步增大，稳定燃烧和不稳定燃烧的喷嘴出口火焰结构均有一定的相似性，且不稳定燃烧的频率相同。

关键词: 全流量补燃循环发动机;喷注器;气气燃烧;相似性;缩尺